The present invention relates to an improved joint lock, and more particularly to a joint lock with a bendable covering sleeve for covering and protecting the steel rope wire of the joint lock. The bendable covering sleeve is composed of a plurality of metal joint units forming a continuous bendable and flexible sleeve. The covering sleeve may replace the complex beading structure of the conventional sleeve, and has advantages of convenience in assembly and lower manufacture cost.
The well-known joint lock is illustrated in FIG. 1, showing the exploded view of the joint lock mechanism. The sectional view of the joint unit which consists of a beading string of the prior art of FIG. 1 is further illustrated in FIG. 2. The prior art joint lock includes a rope wire 10 with a suitable length. A locking member 11 is fixed on one end of the rope wire, and a locking plug 12 is fixed on the other end of the rope wire to form a lock device. In order to protect the rope wire 10 from being destroyed, the rope wire 10 is covered with a plurality of tubes 13 and beads 14 connected in series mechanically to form a protecting sleeve. The tubes and beads are provided with central through hole, so the rope wire 10 may be inserted into the tubes 13 and beads 14. The outer diameter of the bead is larger than the inner diameter of the tube so that the open ends of the tube 13 may engage with the adjacent beads when assembled to form a bendable beading string. In such an arrangement, the assembled beading string is not only capable of protecting the rope wire therein, but also forms a bendable sleeve.
Although the prior art beading string may protect the rope wire against destruction, it has various disadvantages as follows:
1. Higher cost: Because the beading string is composed of a plurality of tube elements and bead elements, it requires two dies to manufacture the elements, thereby causing a higher manufacturing cost. PA1 2. Complex assembly procedure: The beading string must be assembled manually one by one. In assembly, one tube must be followed by a bead, and then the bead must be followed by another tube in sequence to assemble a string. In case of missing any one tube or bead element during assembly, it must be reassembled, which will waste much time and cause inconvenience. PA1 3. Easy to be destroyed: Because the tube of the beading string engages with the outer surface of the bead, the tube and the bead is easy to be damaged during bending operation.